Eight Steps to Building a Defensible E3 Simulation Analysis Plan

Electromagnetic environmental effects (E3) have long been a core part of aircraft certification, but today’s rapidly evolving aerospace landscape has amplified both the complexity and the importance of getting E3 right. As aircraft become more electrified and more tightly integrated, understanding how electromagnetic environments affect both the platform and its system is becoming increasingly challenging.

Electromagnetic simulation has emerged not as a replacement for testing, but as a foundational capability, one that enables smarter design decisions, earlier insight, reduced risk, and more credible certification outcomes.

“Simulation gives you the ability to visualize electromagnetic behavior across the entire aircraft- currents on the wing, fields in cavities, and coupling into cables,” said Cody Weber, co-CEO of Electro Magnetic Applications, Inc. (EMA).

Across the industry, there is a growing push toward standardized guidance for integrating simulation into certification efforts, including the development of ARP 7993, an upcoming document that will help formalize how simulation can support E3 compliance.

The real power of simulation does not come from sophisticated models alone. It comes from having a strong analysis plan.

In this article we will:

• Show how digital twins enhance E3 understanding and reduce testing needs
• Outline why credible E3 simulation requires a structured, traceable analysis plan
• Walk through the key elements of a defensible plan, from scope and assumptions to validation and uncertainty

Understanding the Electromagnetic Environment

Fig. 1. Electromagnetic environmental effects encountered by aircraft

Aircraft are exposed to a wide range of electromagnetic environments at both the aircraft and system level, including:

• Direct and indirect effects of lightning
• High-intensity radiated fields (HIRF)
• Electromagnetic compatibility (EMC) and electromagnetic interference (EMI)
• Radio frequency interference (RFI)

Historically, these environments were understood primarily through heritage experience and physical testing. For new platforms, especially first-of-type designs without precedent, electromagnetic simulation has become one of the most effective ways to characterize how an aircraft responds to these environments.

Simulation as a Digital Twin

Fig. 2. Fully representative aircraft digital twin for E3 evaluation

One of the most transformative concepts in modern simulation is the digital twin.

“The digital twin is a virtual laboratory that lets you analyze how your aircraft’s structures, systems, and components interact under various electromagnetic environments,” Weber explained.

Digital twins allow designers to:

• Visualize current densities across wings, field penetration into cavities, and antenna emissions coupling to cable bundles
• Modify assumptions or design details such as shielding, bonding, or material properties, and immediately see how those changes affect electromagnetic coupling
• Explore regions of the aircraft that may be impractical to probe during physical testing

This virtual environment accelerates learning and helps engineers understand aircraft behavior long before it enters the testing phase.

Structuring Effective E3 Simulation

One of the biggest pitfalls in electromagnetic simulation is jumping straight to a full aircraft model. While engineers often want high fidelity models right away, certification agencies are looking for traceability, justification, and demonstrated understanding.

“Confidence comes from building breadcrumbs,” Weber said. “Small, simple models that show you understand each part of the design.”

A solid analysis plan establishes:

• Scope: What parts of the aircraft will be analyzed
• Assumptions: What parameters, boundary conditions, and simplifications are made
• Outputs: What results the simulation must produce
• Validation method: How the model will be checked against physical reality
• Environment definition: Which electromagnetic conditions are applied

This structure reduces uncertainty and builds confidence both internally and with certification authorities.

Step 1: Define What You’re Analyzing and Why

A solid plan starts with clearly defining the analysis domain, such as:

• The entire aircraft
• A single wing
• The fuselage
• Independently modeled sections brought together later

There is no single correct answer, only what fits your certification strategy. The key is to define it upfront. Ambiguity in scope is one of the most common sources of certification delays Weber pointed out.

Step 2: Identify and Document All Critical Parameters and Assumptions

This is the heart of the analysis plan.

Critical parameters and assumptions must be clearly documented and justified, including:

• Geometry sources: Manufacturing CAD, conceptional design models
• Material properties: Conductivity, resistivity, permittivity, bonding behavior
• Simplifications: Idealized fasteners, omitted features, smoothed surfaces
• Environment definitions: Lightning, HIRF, EMI
• Configuration decisions: Shield types, cable routing assumptions, termination techniques

Each assumption must be listed, traced, defined, and ultimately validated. Uncertainty is overwhelmingly driven by assumptions and regulators will want to know exactly how each was derived.

Step 3: Define the Electromagnetic Environments and Target Outputs

A strong simulation plan clearly defines which electromagnetic environments will be applied and what outputs must be extracted to demonstrate compliance. This upfront clarity ensures the analysis aligns with certification expectations and avoids rework later.

Key environments to specify:

• Direct lightning
• Indirect lightning
• HIRF/ external EMI
• Internal EMI/EMC interactions

Required outputs:

• Cable-level coupling responses
• Field attenuation through structure and routing paths
• Pin-level voltage and current transients

By explicitly connecting environments to measurable outputs, the simulation workflow becomes focused, repeatable, and directly traceable to regulatory certification requirements.

Step 4: Build Confidence Through a Structured, Building-Block Approach

Attempting a full aircraft model too early creates unanswered questions and erosion of authority trust.

“Diving in and doing the full aircraft all at once is not the easiest thing,” Weber stated. “A building-block approach feeds into justification for the full aircraft response.”

Start with the fundamentals:

• Fastener impedance characterization
• Bonding configurations
• Material-level conductivity and resistivity tests
• Cable shield termination and transfer resistance measurements

Move to regional models:

• Cockpit
• Aft fuselage
• Wing section
• Tail assemblies

Then assemble the full aircraft model only once confidence exists in every contributing piece.

Step 5: Plan for Validation

Every credible analysis plan must include a path to validation.

“At the end of the day, you have to do testing, but validated simulations reduce the number of tests you need to perform,” Weber clarified.

Validation can include:

• Direct comparison with lab measurements
• Correlation to characterization test results
• Sensitivity analyses to bound uncertain parameters
• Conservative estimates to ensure safety margins

An analysis plan must detail how each assumption will be checked and how the model will be tuned based on physical data.

“Simple characterization tests from day one feed back into your analysis and build confidence in your approach,” Weber pointed out.

Fig. 5. HIRF testing setup

Step 6: Address Uncertainty and Develop Realistic Margins

Margins must reflect the uncertainty inherent in both the model and environment. There is no single margin appropriate across all electromagnetic scenarios.

“Uncertainty and margin development isn’t simple. You need margins that reflect realistic limits across different environments,” Weber said.

A plan should include:

• An uncertainty assessment for each parameter
• A margin strategy tailored to environment and output type
• A process for tightening margins as model fidelity increases

Good plans clearly explain how margins were derived and how they ensure protection under worst-case but realistic conditions.

“Most of the uncertainty associated with numerical analysis is tied to assumptions,” Weber commented.

Step 7: Leverage Sensitivity Analysis to Strengthen the Plan

Sensitivity analysis is one of simulation’s greatest strengths.

Your plan should incorporate sensitivity studies to:

• Explore parameter ranges that testing cannot cover
• Understand which variables truly drive coupling behavior
• Rapidly compare design alternatives
• Build confidence in assumptions and margins

Weber shared this example. He said changing skin conductivity on a V-tail model dramatically altered cable bundle current levels, from 20,000 amps down to 5,000 amps, as conductivity increased due to lightning protection materials. Shielding variations showed similar reductions in pin-level transients.

Step 8: Anticipate Regulatory Expectations Early

Regulators are moving toward formalized guidance for simulation-based certification. The plan you build today must align with emerging expectations for:

• Model traceability
• Parameter justification
• Validation evidence
• Structured uncertainty evaluation

A solid analysis plan positions your program to meet these expectations proactively.

Ansys EMC Plus for Aerospace Applications

Ansys EMC Plus is designed specifically for analyzing electromagnetic behavior in complex aerospace platforms. Its hybrid solvers of finite-difference time-domain (FDTD), multiconductor transmission line, and circuit, enable accurate evaluation of current flow, field penetration, shielding effectiveness, and transient responses with high accuracy. This allows engineers to identify lightning, HIRF, and EMC coupling risks early in development, when cable routing, bonding strategies, or shielding configurations can still be changed at the model stage rather than prototype testing. Programs that adopt this early simulation workflow often reduce test-lab redesign from multiple iterative rounds to a single, well-scoped verification cycle.

Fig. 7. Ansys EMC Plus integrates a full wave FDTD solver, multiconductor transmission line solver, and circuit solver for fully integrated co-simulation of all three solvers.

The platform’s ability to integrate detailed CAD, material properties, and cable harness definitions makes it well suited for modern electrified airframes, enabling engineers to build credible, defensible E3 simulation evidence early in the development cycle.

Building Trustworthy E3 Simulation

Simulation is indispensable for understanding electromagnetic effects, supporting design decisions, reducing test burden, and ultimately achieving E3 certification. It becomes truly powerful when built on a strong analysis plan; a roadmap that defines scope, assumptions, environments, outputs, validation steps, uncertainty strategies, and confidence-building activities.

A solid analysis plan is not just helpful, it is essential to ensuring simulation results can be trusted by engineering teams and certification authorities alike.

Learn more in the EMA Expo 2026 session “Role of Simulations to Support E3 Design and Certification on Aerospace Platforms.” Watch on demand here.

Partner with experts who can guide the process. EMA works with customers from day one to build a clear, defensible analysis plan. With years of experience developing and validating models and supporting full-aircraft certifications, EMA helps customers navigate each phase to ensure authorities have confidence in the final results.

EMA completes simulation using EMC Plus and offers portable lightning testing equipment, providing flexibility to complete testing on your schedule.

Reach out to EMA today for an EMC Plus demo or to discuss a certification plan.